mdb007

So after reading about the craziness changing plugs and having them break off in the 5.4, do I need to worry about it with the 4.6 on my 04 Heritage? I have 100800 miles and was thinking about it but hell after changing plugs in a bunch of other cars over the years this is the first time I am nervous. And I'm thinking what the hell were ford engineers thinking when they designed these motors. Now this is coming from a guy who grew up on GM small blocks and honda and nissan the past 20 years where i never had issues with plugs. This is my first Ford and I have been impressed with the simplicity of pulling the cluster out to fix the odometer and changing front head/marker lights but the engine seems to be a whole different animal. So any tips or warnings? Should i shoot some PB blaster down in before attempting to change?

thanks

ultimatenoobie

The 4.6 is not a problem usually. It has normal plugs, I think you need Motorcraft SP493. The hard part will be getting the coils out and off in one piece. Have the engine warm. Otherwise it is a normal in and out (Don't over torque!! ). Only use Motorcraft platinum plugs. Yes to the PB Blaster.

akdoggie

Use Motorcraft plugs and torque them to 28 ft pnds. If torqued to spec, the plugs won't blow out. Our GEN 10's don't have the plug breaking apart problems. That's the 4.6/5.4 3V engines in the GEN 11's mostly.

JCR 56

The main one to avoid is the 5.4 3v '04-'08. The 4.6 used standard 1 piece plugs, 2v and 3v.

R&TBabich

I would worry more about leaving the plugs in much longer if they are the OEM plugs.
Other than removing the COPs to get to the plugs they are fairly straight forward to change, other that they are down in a well that catches all sorts of debris.
A set of specialty plug sockets like the Gearwrench 41740D make the job easier.
Be sure to have a vacuum or air compressor handy to clean out the plug wells before removing the plugs.
Use a torque wrench when replacing the plugs.
I would change the boots/springs while in there, the coils will last longer.
A bit of dielectric grease on the boots will make them easier to remove next time.
Inspect all the vacuum hoses while in there, especially the PCV hose.
You can replace/reroute the hoses with longer hoses to gain better access to the plugs.

mdb007

Thanks yeah i was planning on blowing out and running shop vac and planned on doing PCV as thats a 100k mile maintenance item. And use anti seize on threads as well? I bought a big jar of it to do 2 sets of plugs on our cars last year. I have 35 year old spark plug sockets and the gearwrench look thinner so worth the investment. So you guys don't use aftermarket plugs and stick with the Motorcraft? I have used Bosch and NGK and had good luck with those.

R&TBabich

The Motorcraft plugs work great, I change plugs & boots at 50k.
The PCV hose and elbow are plain non reinforced hose.
I rebuilt the PCV hose with reinforced hose and brass connectors/elbow/adapters, should be trouble free for a long time.
Also, replaced all the vacuum hoses with silicone hoses, 10' lengths are reasonable on ebay.

JCR 56

Stick with Motorcraft, can't go wrong.

FranklinF150

This is good to know. I had been under the impression that all 5.4/4.6 were damn difficult to change the plugs as they break easily.

white89gt

BOTH the 4.6 and 5.4 3V came with the 2 piece plugs.

They don't break easily in the 2V, but if they are not torqued properly, as AKdoggie eluded to, they can blow out. I will add one more tidbit to AK's instructions.... and that would be that you do not use anti-seize. It can alter the proper torque value, and if you use Motorcraft plugs, they are already nickle coated to prevent seizing.